yii2 怎么上传图片

main.css 放在frontendwebcss
.onedialog{position:absolute; left: 300px; top: 500px; z-index: 10; width: 700px; height: 400px;border-radius:5px;
box-shadow:5px 2px 6px #000; border: 2px solid #666}
.oneiframe{ width: 100%; height: 100% }

$(function(){
$('#product-picurl').click(function(){
$('#oneupload').remove();
$('<div>').appendTo($('body')).attr({"class":"onedialog",'id':"oneupload"});
$('<iframe>').appendTo($('#oneupload')).attr({"src":"?r=upload","class":"oneiframe"})
});
 var v=$('#product-picurl').val();
if(v){
$('<img>').attr({"src":v,"style":"height:50px"}).insertAfter($('#product-picurl'));
}
});

class AppAsset extends AssetBundle
{
 public $basePath = '@webroot';
 public $baseUrl = '@web';
 public $css = [
 'css/site.css',
 'css/main.css',
 ];
 public $js = [
 'assets/main.js'
 ];
 public $depends = [
 'yiiwebYiiAsset',
 'yiiootstrapBootstrapAsset',
 ];
}

<?PHP
namespace frontendcontrollers;
use Yii;
use yiiwebController;
use appmodelsUploadForm;
use yiiwebUploadedFile;
class UploadController extends Controller
{
 public function actionIndex()
 {
 $model = new UploadForm();
 if (Yii::$app->request->isPost) {
 $model->file = UploadedFile::getInstance($model, 'file');
 if ($model->file && $model->validate()) {
 //$model->file->saveAs('uploads/' . $model->file->baseName . '.' .$model->file->extension); 
 $fileName='uploads/' . date("YmdHis") . '.' . $model->file->extension;
 $model->file->saveAs($fileName);
 }
 echo "<script src='assets/upload.js'></script>;";
 echo "<script>";
 echo "var oneinput=parent.document.getElementById('product-picurl');";
 echo "parent.document.getElementById('product-picurl').value='".$fileName."';";
 echo "var oneupload = parent.document.getElementById('oneupload');";
 echo "var img = document.createElement('img');";
 echo "img.setAttribute('style', 'height:50px');";
 echo "img.src ='".$fileName."';";
 echo "insertAfter(img,oneinput);";
 echo "oneupload.parentNode.removeChild(oneupload)";
 echo "</script>";
 }
 return $this->render('upload', ['model' => $model]);
 }
}
?>

<?PHP
namespace appmodels;
use yiiaseModel;
use yiiwebUploadedFile;
/**
 * UploadForm is the model behind the upload form.
 */
class UploadForm extends Model
{
 /**
 * @var UploadedFile file attribute
 */
 public $file;
 /**
 * @return array the validation rules.
 */
 public function rules()
 {
 return [
 [['file'], 'file'],
 ];
 }
}
?>

<?php
use yiiwidgetsActiveForm;
?>
<?php $form = ActiveForm::begin(['options' => ['enctype' => 'multipart/form-data']]) ?>
<?= $form->field($model, 'file')->fileInput() ?>
<button>Submit</button>
<?php ActiveForm::end() ?>